Discrete phase coupling method based on vortex core excitation in cavitation induced by vortex generators

Abstract

Cavitation is prevalent in various types of fluid machinery. Vortex generators, as key components governing cavitation inception and development, possess small-scale features that challenge conventional numerical methods in accurately capturing vortex-induced flow details. This paper presents a novel discrete bubble coupling numerical methodology that effectively simulates cavitation inception induced by vortex generators and captures high vapor content vortex structures at discrete bubble scales. Furthermore, this work analyzes the periodic characteristics of high vapor content vortex structures caused by the vortex generators in experiments and compares experimental findings with simulation results. The results demonstrate that high vapor content vortex structures are accompanied by the periodic shedding of cavitation clouds, and rapid cavitation inception occurs following re-entrant jet cutting off the cavitation clouds. Numerically, the key structural features of high vapor content vortex structures were captured which aligned the experimentally observed periodic variations. Simultaneously, the discrete phase bubble collapse fluctuation exhibits a time lag relative to the continuous phase vapor volume fraction fluctuation, with a phase lag of approximately 0.225 cycles, attributed to the reduced vapor volume after re-entrant jet cutting off attached cavitation clouds.